Process for the electrolytic decomposition of metal compounds



- June 29, 1943.

W. HONSBERG PROCESS FOR THE ELECTROLYTIC DECOMPOSITION OF METAL COMPOUNDS Filed May 7, 1940 ffwenfir Hefner Patented June 29, 1943 PROCESS FOR THE ELECTROLYTIC DECOM- POSITION OF METAL COMPOUNDS Werner Honsberg, Ludwlgshafen-on-the-lthine Germany; vested in the Alien Property Custodian Application May 7, 1940, Serial No. 333,761 In Germany May 30, 1939 2 Claims.

The present invention relates to a process for the electrolytic decomposition of metal compounds.

In my copending application Ser. No. 274,166, filed May 17, 1939, I have described a process for the electrolytic decomposition of alkali metal or alkaline earth metal compounds in the dissolved or fused state with the use of carrier. surfaces moved subsequently through a bath of liquid metal and the electrolyte so that the surfaces become covered with a coating of liquid metal, and under renewal of the metal bath during the electrolytic treatment. In this process both the FUD, ply of fresh liquid metal and the withdrawal of the liquid metal containing the electrolytically deposited metal take place at the surface of the metal bath. A preferred manner of working according to this process consists in supplying the fresh liquid metal and withdrawing, the liquid metal containing the electrolytically deposited metal in the neighbourhood of the cathode carrier surface and leading the current of liquid metal parallel to the carrier surface. The liquid metal is thus caused to flow in the horizontal plane of the surface of the bath and by this expedient contaminations, as degradation products of the graphite anodes, which would otherwise collect on the surface of the bath, will be carried off and removed from the plant. The bath may thus be kept clean throughout the operation.

I have now found that the said process may also be used for the decomposition of metal compounds other than compounds of alkali metals and alkaline earth metals. In particular, the

process may be advantageously used for the decomposition of zinc salts in order to form zinc amalgam. From the said amalgam the zinc may be recovered by distilling the mercury off. When employing solutions of zinc chloride, chlorine is formed on the anode, just as with the use of alkali metal or alkalin earth metal chlorides, and led off separately.

Several modifications of the process within the scope of the present invention are illustrated in the accompanying drawing, but the invention is not restricted to the particular modifications shown.

Fig. 1 is a prospective view of a cell wherein :lxirtendless band is used as the cathode carrier ace.

Fig. 2 is a diagrammatic view of a decomposition cell having a rotating disc as the cathode carrier surface.

The mercury is contained-in a trough l the surface of which is indicated by lines 5-5. The cell housing containing the electrolyte is not shown so that the carrier band 2 running on rollers I and l, and the anode 1 may be better seen. The current leads are shown at 8 and I. The supply of mercury from the tube II is effected at the surface of the mercury bath by means of a pair of nozzles 9 and the withdrawal takes place through a pair of nozzles It. The mercury is made to circulate through the device by means of a pump I! which conveys the mercury through the device I! in which it is decomposed into mercury and zinc. The regenerated mercury is then supplied to the bath again through pipe II and nozzles 9.

Referring now to Fig. 2, I is the trough for the mercury, line 5-5 showing its surface. Disc I5 is mounted on a shaft I 6, nozzles 9 and It, through which the mercury is introduced and withdrawn respectively, are arranged at the surface of the mercury bath and in the immediate neighborhood of the disc in a manner similar to that shown in Fig. 1.

What I claim is:

1. In a process of electrolytically depositing zinc from an electrolyte bath of zinc salts confined in an electrolytic cell by passing a current through said electrolyte from an anode to a cathode comprising a moving surface coated with mercury and in which the cathode moves alternately through a mercury bath to form said coating and thence through said electrolyte, the improvement which comprises continuously introducing fresh mercury at the surface of the mercury bath near one end of said cell and continuously withdrawing mercury and zinc amalgam from said surface near the other endof said cell and thereby causing a current of mercury and zinc amalgam to move continuously at the surface of the mercury bath and parallel to said moving surface.

2. A process as defined in claim 1 wherein the electrolyte comprises zinc chloride.

WERNER. HONSBERG. 

